On the accuracy of Merk's method for solution of laminar boundary-layer equations

1971 ◽  
Vol 23 (1) ◽  
pp. 426-430 ◽  
Author(s):  
G. Abad ◽  
W. R. Schowalter
Keyword(s):  
Boundary Layer ◽  
Laminar Boundary Layer ◽  
Boundary Layer Equations

The Critical Height of Distributed Roughness to Cause Boundary Layer Transition

1959 ◽  
Vol 63 (588) ◽  
pp. 722-722
Author(s):  
R. L. Dommett
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Laminar Boundary Layer ◽  
Boundary Layer Transition ◽  
Critical Height ◽  
Layer Transition ◽  
Local Conditions ◽  
Additional Advantage ◽  
Boundary Layer Equations ◽  
General Method

It has been found that there is a critical height for “sandpaper” type roughness below which no measurable disturbances are introduced into a laminar boundary layer and above which transition is initiated at the roughness. Braslow and Knox have proposed a method of predicting this height, for flow over a flat plate or a cone, using exact solutions of the laminar boundary layer equations combined with a correlation of experimental results in terms of a Reynolds number based on roughness height, k, and local conditions at the top of the elements. A simpler, yet more general, method can be constructed by taking additional advantage of the linearity of the velocity profile near the wall in a laminar boundary layer.

On the propagation of disturbances in a laminar boundary layer. I

1973 ◽  
Vol 73 (3) ◽  
pp. 493-503 ◽  
Author(s):  
S. N. Brown ◽  
K. Stewartson
Keyword(s):  
Boundary Layer ◽  
Asymptotic Formula ◽  
Boundary Conditions ◽  
Laminar Boundary Layer ◽  
Numerical Results ◽  
Boundary Layer Equations ◽  
Displacement Thickness ◽  
Layer I

An analysis is made of the response of a laminar boundary layer to a perturbation, either in the mainstream, or of the boundary conditions at the wall. The disturbance propagates with the mainstream velocity, and the manner in which it decays at large distances downstream is determined by eigensolutions of the boundary-layer equations. The elucidation of the structure of these eigensolutions requires division of the boundary layer into three regions. Comparison of the asymptotic formula obtained for the displacement thickness is made with the numerical results of Ackerberg and Phillips (1).

The Laminar Boundary Layer on a Hot Cylinder Fixed in a Fluctuating Stream

1961 ◽  
Vol 28 (3) ◽  
pp. 339-346 ◽  
Author(s):  
R. J. Gribben
Keyword(s):  
Boundary Layer ◽  
Mach Number ◽  
Laminar Boundary Layer ◽  
Small Amplitude ◽  
External Flow ◽  
Low Speed ◽  
Boundary Layer Equations ◽  
Special Cases ◽  
Exact Calculations ◽  
Small Amplitude Oscillation

The equations for nonsteady, two-dimensional low-speed compressible flow in the laminar boundary layer are solved approximately by use of the Pohlhausen technique with the assumption of quartic profiles for the velocity and temperature. The external flow considered is of the form of a steady basic velocity with a superimposed small amplitude oscillation such as may arise, for example, when a sound wave is present in a uniform incident stream. The analysis is then applicable to the case of a hot cylinder fixed in such a stream. Terms of the order of the incident stream Mach number are neglected in the expressions for external flow quantities (whereas the low-speed boundary-layer equations involve errors of the order of only the square of this Mach number). Two special cases are worked out—the flow over a flat plate for which there is fair agreement with available exact calculations, and the flow over a circular cylinder.

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